K-1766 shelf life and disposal

[eco-help]

I bought the kit (from TFTestkits) K-1766 2 years ago.. hardly used it.. recently did use and it seems fine.
I had to re-order the primary refills… so to meet the $100 free shipping and being not sure about shelf life I ordered the refills for k-1766.
Now I ponder: I have used maybe 1% of these “old” chemicals can I keep using them instead of disposing? If not how best to dispose? I live on a lake….
Do these really expire? Can I just keep using the old ones? How will I know they expired?

 

[ajw22]

The silver nitrate reagent in the K-1766 is very stable and will last for years. Just keep on using what you have.